Remove ALL burn applications. What are the specs of your PC?
Connect ONLY the hard drive as the MASTER drive on the Primary IDE channel. Leave the Slave connector unplugged.
Connect ONLY the NEC 3520 as the MASTER drive on the Secondary IDE channel. Leave the Slave connector unplugged.
Boot into BIOS and verify that the hard drive and NEC optical drive are detected and running in DMA mode. Set the BIOS to AUTO detect these devices. Save and exit.
Boot into DEVICE MANAGER and remove the PRIMARY AND SECONDARY IDE CHANNELS. Reboot PC. Set Devices 0 and 1 in the PRIMARY AND SECONDARY IDE CHANNELS to use DMA mode. Reboot and verify that the hard drive is running at DMA mode 4 or higher, and NEC is running at DMA mode 2.
Now download CloneDVD and AnyDVD from Slysoft.com and install these applications. Launch AnyDVD and attempt to backup a DVD movie using CloneDVD. Set the burn speed to 4X.
DO NOT deviate from these steps.